
/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "SampleCode.h"
#include "SkView.h"
#include "SkCanvas.h"
#include "SkGradientShader.h"
#include "SkGraphics.h"
#include "SkImageDecoder.h"
#include "SkPath.h"
#include "SkRegion.h"
#include "SkShader.h"
#include "SkUtils.h"
#include "SkXfermode.h"
#include "SkComposeShader.h"
#include "SkColorPriv.h"
#include "SkColorFilter.h"
#include "SkTime.h"
#include "SkTransparentShader.h"
#include "SkTypeface.h"

static SkShader* make_bitmapfade(const SkBitmap& bm)
    {
    SkPoint pts[2];
    SkColor colors[2];

    pts[0].set(0, 0);
    pts[1].set(0, SkIntToScalar(bm.height()));
    colors[0] = SK_ColorBLACK;
    colors[1] = SkColorSetARGB(0, 0, 0, 0);
    SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);

    SkShader* shaderB = SkShader::CreateBitmapShader(bm,
                        SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);

    SkXfermode* mode = SkXfermode::Create(SkXfermode::kDstIn_Mode);

    SkShader* shader = new SkComposeShader(shaderB, shaderA, mode);
    shaderA->unref();
    shaderB->unref();
    mode->unref();

    return shader;
    }

class ShaderView : public SampleView
    {
    public:
        SkShader*   fShader;
        SkBitmap    fBitmap;

        ShaderView()
            {
            SkImageDecoder::DecodeFile("/skimages/logo.gif", &fBitmap);

            SkPoint pts[2];
            SkColor colors[2];

            pts[0].set(0, 0);
            pts[1].set(SkIntToScalar(100), 0);
            colors[0] = SK_ColorRED;
            colors[1] = SK_ColorBLUE;
            SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);

            pts[0].set(0, 0);
            pts[1].set(0, SkIntToScalar(100));
            colors[0] = SK_ColorBLACK;
            colors[1] = SkColorSetARGB(0x80, 0, 0, 0);
            SkShader* shaderB = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);

            SkXfermode* mode = SkXfermode::Create(SkXfermode::kDstIn_Mode);

            fShader = new SkComposeShader(shaderA, shaderB, mode);
            shaderA->unref();
            shaderB->unref();
            mode->unref();
            }
        virtual ~ShaderView()
            {
            SkSafeUnref(fShader);
            }

    protected:
        // overrides from SkEventSink
        virtual bool onQuery(SkEvent* evt)
            {
            if (SampleCode::TitleQ(*evt))
                {
                SampleCode::TitleR(evt, "Shaders");
                return true;
                }
            return this->INHERITED::onQuery(evt);
            }

        virtual void onDrawContent(SkCanvas* canvas)
            {
            canvas->drawBitmap(fBitmap, 0, 0);

            canvas->translate(SkIntToScalar(20), SkIntToScalar(120));

            SkPaint paint;
            SkRect  r;

            paint.setColor(SK_ColorGREEN);
            canvas->drawRectCoords(0, 0, SkIntToScalar(100), SkIntToScalar(100), paint);
            paint.setShader(fShader);
            canvas->drawRectCoords(0, 0, SkIntToScalar(100), SkIntToScalar(100), paint);

            canvas->translate(SkIntToScalar(110), 0);

            int w = fBitmap.width();
            int h = fBitmap.height();
            w = 120;
            h = 80;
            r.set(0, 0, SkIntToScalar(w), SkIntToScalar(h));

            paint.setShader(NULL);
            canvas->drawRect(r, paint);
            paint.setShader(make_bitmapfade(fBitmap))->unref();
            canvas->drawRect(r, paint);

            paint.setShader(new SkTransparentShader)->unref();
            canvas->drawRect(r, paint);
            }

        virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y)
            {
            this->inval(NULL);
            return this->INHERITED::onFindClickHandler(x, y);
            }

        virtual bool onClick(Click* click)
            {
            return this->INHERITED::onClick(click);
            }

    private:
        typedef SampleView INHERITED;
    };

//////////////////////////////////////////////////////////////////////////////

static SkView* MyFactory()
    {
    return new ShaderView;
    }
static SkViewRegister reg(MyFactory);

